Baselines, Impacts and Mitigation Strategies for Plastic Debris and Microplastic Pollution in South East Asia

Plastic waste accumulation in the environment was first documented in the 1970s with the discovery of plastics in the marine environment. Plastic waste has increased significantly due to the continuing expansion of worldwide plastic production, with Asian countries dominating the global plastics producer. The enormous production of plastics, together with their low recycling rates has, in a few decades, resulted in the accumulation of plastic wastes on land and diversification towards the open and deep sea due to mismanaged plastic waste disposal. Tonnes of plastic from terrestrial sources are transported to the sea via riverine system pathways, leading to worsening pollution. Plastic debris present in the environment is subjected to degradation processes such as mechanical erosion (abrasion), chemical degradation (photochemical), or biological processes forming plastic fragments. The rate of degradation and persistency varies on polymer type, shape, and density. As a consequence of degradation, plastics are transformed into microplastics (< 5 mm), mesoplastics (5-25 mm), and macroplastics (> 25 mm). The transport and fate of these pollutants bring about many issues. They have been discovered in freshwater and marine environments, mangrove ecosystems, rivers, lakes, and ponds. Additionally, numerous studies have demonstrated that microplastics are consumed by a variety of organisms. The occurrence of plastic debris and microplastics in South East Asia has been documented but is still limited. The region is becoming a hot spot for microplastic and plastic pollution with major rivers listed among the top for global distribution of plastic emissions. Countries such as Indonesia, Malaysia, Thailand, the Philippines and Vietnam were ranked among the top producers, while there is still a lack of data for countries such as Brunei, Cambodia, Vietnam, Lao, Myanmar and Singapore. Despite the growing number of publications on the topic, large gaps remain, especially regarding their source, transport, and fate of these emerging pollutants in the marine environment, particularly in the South East Asia region. By providing baseline data in addressing plastic emissions, effective mitigation strategies could be established in dealing with this emerging issue.

A call for top-quality research articles, especially in the occurrences, distribution, abundance, quantification and characterization of microplastics and marine plastic debris in the South East Asia region is necessary. Limited data concerning the actual concentration, distribution and status of these emerging contaminants in the region has been published. This Research Topic will act as a platform to exchange knowledge and current practices/methodologies in microplastics and plastic debris research, providing room for mitigation strategies, and hopefully contributing to the UN Decade for Sustainable Development 2030 and the Ocean Decade Implementation plan for plastics in the oceans.

Research concerning baseline data, simulation and modelling studies, and research on the fate and transport of the pollutants are highly encouraged. This Research Topic welcomes themes including but not limited to the occurrences, distribution, quantification and identification (physical and chemical analysis) of microplastics in the environmental matrices such as marine/sea water, coastal sediment and seabed, estuarine and other environmental compartments (e.g air), as well as biota from South East Asia. Original research articles and review articles that address the degree and status of plastic pollution in South East Asian countries also are welcome.